A head lamp of a vehicle is used to project light ahead of the vehicle during driving. A light source is installed inside the head lamp, and light from the light source is projected upward or downward ahead of the vehicle.
The head lamp is in a high-temperature environment caused by heat of the light source of the head lamp, heat transferred from an engine of the vehicle, etc. Thus, a temperature difference occurs between the head lamp and the outside and thus condensation may form inside the head lamp.
When the inside of the head lamp gets damp, the light source of the head lamp may malfunction and the marketability of the head lamp may decrease, and thus condensation has been recognized as a chronic problem in a vehicle head lamp system. Accordingly, various solutions thereto have been introduced but a fundamental solution has yet to be provided.